Revisions to List of Hazardous Air Contaminants

Appendices B and C of the Vermont Air Pollution Control Regulations list the regulated Hazardous Air Contaminants (HACs) in Vermont.  In accordance with 5-261(6) of the Vermont Air Pollution Control Regulations, the Secretary may add additional chemicals or compounds to the list of regulated HACs, if appropriate, provided sufficient health data are available.  Further, if additional scientific data becomes available that warrants adjusting an existing standard, including default values, for a HAC listed in Appendices B and C, the Secretary may on a case-by-case basis adjust the standard for the chemical or compound.

All additions of a new chemical or compound or revisions to an existing chemical or compound are open for public comment for a period of thirty days from the date proposed.  Comments may be submitted to:

Attn: HAC Revisions
Air Quality and Climate Division
Davis 2
One National Life Drive
Montpelier, VT 05620-3802
(802) 828-1288

Recently Adopted Additions and Revisions to the List of Hazardous Air Contaminants
HAC Name and CAS Date Adopted or Proposed Existing HAAS (ug/m3) Existing AL (lbs/8-hours) Proposed HAAS (ug/m3) Proposed AL (lbs/8-hours)
Recently adopted additions of new HACs to Appendices B and C: 1
Category I
n-Propyl bromide
106-94-5
August 15, 2019 Na Na 10.0 0.83
Recently adopted revisions to existing HACs in Appendices B and C: 1
Acrylamide 2
79-06-1
August 15, 2019 0.00076 0.000063 0.01 0.00083
Benzo-a-pyrene 2
50-32-8
August 15, 2019 0.00048 0.000040 0.0017 0.00014
Carbon tetrachloride 2
56-23-5
August 15, 2019 0.066 0.0055 0.17 0.014
Chloroprene 2
126-99-8
August 15, 2019 0.7 0.06 0.0033 0.00027
Dioxane 2
123-91-1
August 15, 2019 0.32 0.027 0.2 0.016
Ethylene dibromide 2
106-93-4
August 15, 2019 0.0045 0.00037 0.0017 0.00014
Ethylene oxide 2
75-21-8
August 15, 2019 0.01 0.00083 0.00033 0.000027
Methylene chloride 2
75-09-2
August 15, 2019 2.1 0.17 100 8.3
Nitrobenzene 2
98-95-3
August 15, 2019 0.15 0.012 0.025 0.0021
Tetrachloroethylene 2 August 15, 2019 0.18 0.015 3.85 0.32
Trichloroethylene 2
79-01-6
August 15, 2019 0.5 0.04 0.24 0.02
Proposed Additions and Revisions to the List of Hazardous Air Contaminants
HAC Name and CAS Date Adopted or Proposed Existing HAAS (ug/m3) Existing AL (lbs/8-hours) Proposed HAAS (ug/m3) Proposed AL (lbs/8-hours)
Proposed additions of new HACs to Appendices B and C:
None          
Proposed revisions to existing HACs in Appendices B and C:
None          

  


1 All recently adopted additions and revisions in the table above shall be of the same effect as if said contaminant and new values were listed in Appendices B and C of the  Vermont Air Pollution Control Regulations and, in the case of revisions, shall supersede the existing values in Appendices B and C.

2 The revisions to each of the listed chemicals and compounds are based solely on the latest US EPA Integrated Risk Information System (IRIS) inhalation unit risk (IUR) factor which has been updated since the adoption of the existing standard.